Occurrence of androgen receptor gene CAG trinucleotide sequence polymorphism in the metropolitan population of Polish men

Abstract

Background: The activity of androgen receptor (AR) is modulated by a polymorphic region located within exon 1 its gene and characterizing a variable number of trinucleotide CAG repeats. The length of polymorphic region is inversely correlated with the transactivation function of AR gene. It was showed an ethnic differences existence in the length CAG repeats of AR gene. The aim of the study was determined of the number CAG repeats AR gene occurrence in the population Polish men.
Material and methods: In the population-based cross-sectional study participated a population-based sample randomly selected 466 men aged 25-65 years - residents of Wroclaw, Poland. The CAG polymorphism was amplified by PCR method.
Results: The range of androgen receptor CAG repeats was from 1 to 57 with a mean 24 ± 7,68. The most frequent repeat was 21. It was indicated in 34 (7,3%) of examined subjects. The number of triplets ≤ 20 had 137 (29,4%) men and > 20 329 (70,6%) men. There were no differences in the length of CAG repeats among the age groups. Both the distribution of small (≤ 20) and large (> 20) number CAG repeats and age structure in men groups with the longer and shorter alleles were statistically all the same.
Conclusions: The average number of AR gene CAG repeats and its range in the population Polish men were larger in comparison to the west European populations and more reminded the number repeats distribution meeting among Asians. This ethnic differences might explain the biological variabilities among different populations and another risk of hormone-dependent diseases occurrence.